Sleep Section

What health problems does chronic sleep deprivation lead to?

- obesity - diabetes - cardiovascular disease

How does sleep effect consolidation?

- participants took a nap after learning a non declarative memory task - those who didn't nap was worse than it had been at end of training - those who entered slow wave sleep during their name did the same as they had done at end of training - participants who entered REM sleep performed significantly better; REM strongly facilitated consolidation of memory

What is REM sleep behavior disorder?

- patients fail to exhibit paralysis during REM sleep, causing them to act out their dreams - associated w/ neurodegenerative disorders like Parkinson's or caused by brain damage - treated by clonazepam (a benzodiazepine)

What are sleep attacks?

- primary symptom of narcolepsy - it is an overwhelming urge to sleep that can happen at any time, but typically occurs under boring conditions - sleep lasts 2-5 mins, and person wakes up refreshed

sleep improvement

- routine bedtime and wake time - no bright light at bedtime - watch what you or drink - write a worry or to do list - if you can't sleep after 20 min, leave the room - prioritize time management during day

How does secretion of chemicals from the SCN control circadian rhythms?

- secretion of chemicals diffuses the brain's extracellular fluid, this chemical is prokineticin 2 (PK2), which is a protein in a subset of SCN neurons. - chemicals secreted by SCN cells affect sleep and waking rhythms by diffusing into SPZ and binding w/ receptors on neurons there

What is role of serotonin in arousal?

- serotonin found in raphe nuclei, found in reticular formation - serotonin affections thalamus, hypothalamus, basal ganglia, HC, and neocortex - stimulation of raphe nuclei causes locomotion and cortical arousal; facilitates continuous, automatic movements (pacing, grooming, chewing) but don't respond to novel stimuli - suppresses processing of sensory info in order to prevent disruptions of ongoing activity

What if you get light at the wrong time?

- suppresses melatonin secretion from pineal gland - light after sun goes down is bad - brain sees no difference between light of sun vs light from technology

What is cataplexy?

- symptom of narcolepsy that causes muscular paralysis at inappropriate tines. - Loss of muscle tone is caused by an inhibition of motor neurons in the spinal cord. When this happens, person loses control of their muscles but is still able to breath and control eye movements. - typically precipitated by strong emotional reactions or sudden physical effort (like laughter or throwing an object)

Sleep spindles are:

12-14HZ

What does EEG stand for?

Electroencephalogram

How is brain activity ine sleep studies recorded?

Electroencephalogram (EEG)

sleep deprivation affects what?

Executive function

What assists in brain restoration during sleep?

Glymphatic system

What is the real name of H.M.?

Henry Molaison

Where are place cells found?

Hippocampus

What areas of the brain are involved in arousal/wakefulness?

Locus coeruleus, raphe nuclei, tuberomammillary nucleus, dorsal pons, and basel forebrain

What does the Digit Span + 1 Test assess?

Long Term Memory

What does Fatal Familial Insomnia resemble?

Mad Cow Disease Creutzfeldt-Jakob Disease

Which part of the brain is damaged in Korsakoff's amnesia

Mediodorsal nucleus

THE SCN makes indirection connections to what part of the hypothalamus and are involved in melatonin release? A. Paraventricular nucleus

Paraventricular nucleus

Neurons in which of the following areas may be responsible storing memories of visual input?

Perirhinal cortex

The reticular formation

Plays a role in sleep

What does the Mirror-Drawing Test assess?

Procedural memory

What stage of sleep has dreams?

REM

What is sleep paralysis?

REM sleep paralysis is an ability to move before onset of sleep or when waking in the morning - mental components of REM sleep intrude into sleep paralysis: person dreams while lying awake. This is called hypnagogic hallucinations.

Which of the following occurs during REM sleep?

Rapid eye movement Dreams

When does repolarization occur?

Rising phase and hyperpolarization

What is the preoptic area of the brain?

The preoptic area is the anterior hypothalamus, which is most involved in sleep control. It contains neurons whose axons form inhibitory synaptic connections w/ brain's arousal neurons. When preoptic neurons (sleep neurons) are active, they suppress our arousal neurons. - destruction of preoptic area produces insomnia

What is the molecular ticking of the clock?

There are genes in every cell that code for proteins that are then transcribed. Their job is to stop their own transcription until proteins degrade. This occurs in a 24 hour cycle

What waves are prominent in the 1st stage of sleep (N1)?

Theta waves

What is a characteristic of explicit memories?

They are declarative

What is the order to derivatives for monoamines?

Tyrosine>l-dopa>dopamine>norepinephrine>epinephrine

Sleep stages

Wakefulness (stage W) NREM 1 NREM 2 NREM 3 REM

How does caffeine work?

caffeine blocks adenosine receptors to reduce sleepiness

Alpha activity

consists of regular, medium-frequency waves of 8-12 Hz (hertz, measures cycles per second) - produces activity when a person is resting quietly, not aroused or excited to engaged in strenuous mental activity

What brain regions are involved in maintaining circadian rhythms?

region of the hypothalamus called the suprachiasmatic nucleus (SCN), receives light info from the environment and uses it to entrain behaviors to a 24 hour light/dark cycle - primary biological clock is found in the SCN and times sleep cycles

What is true of Korsakoff's Syndrome amnesia?

related to damage of the hypothalamus

what neurotransmitter do sleep neurons release?

sleep neurons release inhibitory NT GABA and send it to five brain regions involved in arousal, inhibiting their activity

What is the circadian clock regulated by?

suprachiasmatic nuclei

What is true of posttraumatic amnesia?

features retrograde amnesia of events before a blow to the head

What is the effect of genetic factors on sleep?

genetics affect duration of a person's slow wave sleep - one factor: variability in gene that encodes enzyme adenosine deaminase, which breaks down adenosine. These people spend more time in SWS in order to break down adenosine

Kimberly decides to try benzodiazepines to help her sleep. Which of the following could she experience when stopping or starting the drug?

latrogenic insomnia (rebound insomnia)

What are ionotropic receptors activiated by?

ligands

Electroencephalogram (EEG)

monitors brain activity; record from many neurons at once, reporting on sum of electrical activity

Electromyogram (EMG)

monitors muscle activity

hyponic jerks

muscle contractions followed by relaxation

What is nacrolepsy?

neurological disorder characterized by sleep at inappropriate times symptoms: - sleep attacks - cataplexy - sleep paralysis

What is a sleep-related eating disorder?

people who eat during the night while sleeping; typically become overweight - responds to dopaminergic agonists or topiramate (antiseizure meds) - may be a hereditary role

When hyperpolarization occurs the graph moves?

away from -65 mV

What keeps flip flop in "wake" state

activation of orexinergic neurons in lateral hypothalamus

what is secondary insomnia?

an inability to sleep due to a mental or physical condition, like pain, substance use, psychological, or neurological condition

What is the cause of intracellular ticking?

- Circadian rhythms in SCN are produced as protein production rises to a certain level in cell - when maximal level is reached, high concentration of protein in cell turns off its own production through negative feedback loops, resulting in the levels of the protein declining. This removes inhibition, which starts production cycle again. - 7 genes and proteins are involved and have two interlocking feedback loop. Intracellular ticking is regulated by time it takes to produce and degrade a protein set.

What are characteristics of neurotransmitters?

- Neurotransmitters bind to receptor cells. - Neuropeptides are a type of neurotransmitter that are very large. - Agonists are used to increase a drugs effect on neurotransmitters. - Neurotransmitters are only found in the brain and spinal cord (CNS)

How do the flip-flop circuits of REM sleep work?

- REM flop-flop controls cycles of REM and SWS - region of dorsal pons contains REM-ON neurons (fire at high rate during REM) - region of dorsal midbrain contains REM-OFF neurons, cells, that supress REM - mutual inhibition of regions causes flip-flop - REM-OFF receives excitatory input from orexingeric neurons, activation tips REM into off state - when it switches into sleep phase, SWS begins. Activity of orexingeric, noradrenergic, and serotonergic input decreases into REM-OFF, REM sleep will switch to on state and begin

How do flip-flop circuits control REM muscle paralysis?

- REM sleep causes muscle paralysis BUT unless you have a REM sleep behavior disorder and fail to become paralyzed, which causes them to act their dreams - neurons by the REM-ON region excite inhibitory interneurons that are connected to motor neurons, but damage to REM-ON removes this inhibition

What is the difference between consolidation in REM sleep versus consolidation in slow wave sleep?

- REM sleep consolidates non-declarative memories - slow wave sleep consolidations declarative memories; during SWS the brain rehearses info that was acquired during wakefulness

How is the circadian rhythm synchronized?

- SCN receives input from retina through the retinohypothalamic pathway - there is a photoreceptor called melanopsin that provides info about ambient light levels, which synchronizes circadian rhythms - melanopsin ganglion cells are involved in the pupil's response to light because it detects light levels

What is the flip flop circuit?

- Sleep neurons receive inhibitory input from the same regions they inhibit. These NTs are histamine, serotonin, and norepinephrine. - when flip flop is in "wake" state, arousal systems are active and preoptic area is inhibited - when flip flop is in "sleep" state, arousal systems are inhibited and preoptic area is active

Sleep neurons are most commonly located where?

- Ventrolateral preoptic area - median preoptic nucleus

What is process S?

- When sleep deprived, its marked by a biological substance in the CSF that is sleep - adenosine builds up during day and only goes away in SWS

What neurons play a role in alertness and wakefulness?

- acetylcholine (released from cortex and hippocampus) - norepinephrine - serotonin - histamine - orexin

What are drugs that treat narcolepsy?

- methylphenidate (ritalin) treats sleep attacks - REM sleep phenomena alleviated by antidepressants, which can serotonergic and noradrenergic activity - modafinil is a stimulant that treats nacrolepsy

How does melatonin help us sleep?

- affects sensitivity of SCN neurons to zeitgebers and can also alter circadian rhythms - melatonin reaches highest levels around bedtime. Taking melatonin reduces adverse affects of jet lag and work shift changes. Melatonin resynchronizes people with blindness

What are some maladaptive behaviors that occur during SWS?

- bedwetting - sleepwalking - night terrors

What do antagonists do?

- blocks synthesis of NTs by destroying synthesizing enzymes - causes NT to leak from vesicles and be destroyed by degrading enzymes - blocks release of NT from terminal buttons - drug activates autoreceptors and inhibits NT release - drug is a receptor blocker that binds to postsynaptic receptors and blocks effect of NT

What are mechanisms that monitor amount of sleep we need?

- body produces sleep promoting substance that accumulates during wakefulness and destroyed during sleep; here are two substances for each stage of sleep. Sleep promoting chemicals are produced in the brain - adenosine is a sleep promoting substance that builds up during day.

What is the role of norepinephrine in arousal?

- catecholamine agonists produce arousal and sleep, which is mediated by the locus coeruleus (in dorsal pons). Neurons in LC release norepineprhine throughout neocrotex, HC, thalamus, cerebellar cortex, pons, and medulla - firing rate of LC neurons high during wakefulness, low during SWS, and 0 during REM - activation of LC neurons and release of norepinephrine increase vigilance

what role does orexin play in arousal?

- cause of narcolepsy is degeneration of orexin neurons - cells bodies of neurons that secrete orexin are in lateral hypothalamus; axons of neurons project to every part of brain (cerebral cortex, all regions involved in arousal ) - neurons fire at high rate during alert or active waking and a low rate during quiet wake, SWS, and REM

What is delayed sleep phase syndrome?

- caused by mutation of per3 gene on chromosome 1 - 4 hour delay in sleep/waking rhythms - people w/ disorders are unable to fall asleep before 2 am and can't wake up before midmorning

What is advanced sleep phase syndrome?

- caused by mutation on chromosome 2 of a gene involved in intracellular ticking feedback loops - syndrome causes 4-hour advance in rhythms of sleep and temp. cycles (fall asleep around 7:30 and wake up at 4:30 am) - changes relationship between zeitgeber of morning light and the phase of circadian clock that operates in SCN cells.

What are treatment options for insomnia?

- cognitive behavior therapy, progression relaxation techniques, and changes in sleep hygiene (having a consistent sleep schedule, keeping bedrooms dark and quiet) - Pharmalogical interventions include drugs called hypnotics or GABA receptor agonists (VLPO uses GABA indicates a desire to sleep) - sleep deprivation: uses minimizing a sleep schedule to make you more tired, in order to rehabilitate you

What is the function of the pineal gland?

- controls seasonal rhythms - sits on top of midbrain, in front of cerebellum - secretes hormone called melatonin which controls seasonal rhythms - Neurons in SCN make indirect connections to pineal gland, allowing SCN to control melatonin secretion

What causes nacrolepsy?

- degeneration of orexinergic neurons - without orexin, sleep/waking flip flop is unstavke - release of orexin in REM-OFF keeps the REM flip-flop in the off state - With no more orexinergic neurons, emotional episodes like laughter or anger (activate amygdala) tip REM flip-flop into on state; results in a cataplexy attack because loss of orexinergic neurons removes an inhibitory influence of the hypothalamus on the amygdala

What did Michel Siffre do?

- he lived unground in a cave for 6 months - lost track of time at 25 days - his sleep/wake cycles last 18-52 hours - he became suicidal and depressed

What is the physiological basis of Narcolepsy?

- hereditary disorder found in gene but is strongly influenced by unknown environmental factors - found in dogs that mutation of a gene is responsible for canine narcolepsy; it is mutation of the orexin-B receptor. - destruction/loss of orexin neurons is cause of narcolepsy. Hypothesis is that mutations are caused by a hereditary disorder that attacks the immune system of the neurons

What is the function of melatonin?

- in response to SCN input, pineal gland secretes melatonin during night - melatonin acts on various brain structures and control hormones, physiological processes, and behaviors that show seasonal variation - melatonin is released by pineal gland during dark period. Light info relayed from retina to SCN and PVN suppresses release of melatonin

What do agonists do?

- increase synthesis of NT molecules - increase number of NT by destroying degrading enzymes - increases release of NT from terminal buttons - binds to autoreceptors and blocks inhibitory effect on NT release - binds to postsynaptic receptors and either activates or increases effect on NT molecules - blocks deactivation of NT by blocking degradation or reuptake

What happens when adenosine accumulates?

- inhibition of neural activity - produces cognitive and emotional effects seen during sleep deprivation

Role of acetylcholine during wakefulness?

- involved in arousal, especially in cerebral cortex - Two groups, one in pons and one in basal forebrain, produce activation and desynchrony when stimulated - third group located in medial septum controls activity of hippocampus - ACh high in hippocampus and neocortex (both involved in arousal) during waking and REM sleep (desynchronized during this) but low during SWS (synchronized) - increased in ACh in dorsal pons and basal forebrain

What role does histamine play in wakefulness?

- located in tuberomammillary nucleus of hypothalamus, and releases chemicals in cerebral cortex, thalamus, basal ganglia, basal forebrain - increases cortical activation and arousal and project to acetycholine neurons, increasing their release - activity is high during waking but low during SWS and REM

What are implicit/non-declarative memories?

- memories gained through experience and practice that don't involve an attempt to "memorize" info, like learning to drive a car or muscle memory

What is explicit/declarative memory?

- memories of past episodes in life - memories of relationships between stimuli or events

How do flip-flop circuits relate to cortical arousal, rapid eye movements, and genital activity?

- neurons in REM-ON region send axons to regions of thalamus involved in cortical arousal - activation of forebrain neurons by glutamatergic and acetylcholinergic neurons causes arousal and desynchrony - Acetylcholinergic neurons in pons are active during REM sleep causing genital activation; pontine neurons may also be connected w/ neurons in preoptic area and are responsible for erections

What activates orexin?

- orexinergic neurons receive excitatory signal from biological clock that controls rhythms of sleep and waking - neurons receive signals from brain mechanisms that monitor an animal's nutritional state; if an animal is hungry orexinergic neurons will keep them away - involved in homestatic, allowstatic, and circadian

What is the SCN's biological clock?

- the SCN has a physiological mechanism that parses time into units - the SCN has daily activity rhythms, indicating that the circadian clock is there - "ticking" of biological clock w/in SCN is due to activity w/in neurons. Neurons have shown that they have individual, independent, circadian rhythms

What is the impact of an abrupt change in circadian rhythms?

- when there is an abrupt change in someone's rhythm of activity, their internal circadian rhythm is desynchronized with external environment - this causes sleep disturbances, mood changes, and difficulty in functioning - also causes ulcers, depression, and accidents

how is nacrolepsy treated?

- with modafinil: drug that suppresses drowsiness - it stimulates release of orexin which activates release of histamine

What characterizes REM sleep?

- you have vivid dreams - rapid eye movement - blood pressure increases - breathing and heart rate increase - muscle paralysis

What waves are prominent in the resting (awake) brain?

Alpha waves

What synapses terminate onto dendritic spines?

Axosomatic

What are circadian factors?

Circadian factors (aka time of day factors) restrict period of sleep to a certain portion of day/night

What is necessary for long-term potentiation?

Co-occurrence

what are dopamine agonists?

Cocaine MAO inhibitor L-Dopa

What are circadian rhythms?

Daily rhythms in behaviors and physiological processes; approximately a 24 hour cycle - some of the rhythms are started by passive responses to change in illumination - others are controlled by internal clocks which cycle for 25 hours

What do voltage gated ion channels open in response to?

Depolarization

Which type of memory does the Digit span + 1 test evaluate?

Explicit long-term memory

Which type of memory does the delayed non-matching to sample test evaluate

Explicit visual long-term memory

What is sleep apnea?

Form of insomnia caused by an inability to sleep and breath at the same time. Patients fall asleep and cease breathing. - During a period of sleep apnea, level of carbon dioxide in blood stimulate chemoreceptors (neurons that detect presence of certain chemical). The oxygen of blood will then return to normal, person will fall asleep, and cycle begins again - CPAP gives pressured air at night to keep air pathways open

What is a zeitgeber?

German for "time giver"; synchronizes endogenous rhythm - light, clocks, time cues are zeitgebers

What does the Block-Tapping Memory-Span Test assess?

Global Amnesia

How are adenosine and glycogen related?

Glycogen, a carbohydrate is converted into fuel for neurons. Fall in glycogen causes increase in level of adenosine, which has inhibitory effect on neural activity. During sleep stock of glycogen is renewed.

Which type of memory does the incomplete images test evaluate?

Implicit repetition priming

What are names for second messenger receptors?

Metabotropic and G-protein linked

What type of conduction flows from the cell body to the axon terminals?

Orthodromic

How are memories formed?

You are activating many regions of the brain that signal to hippocampus. Any "what" info goes through perirhinal cortex and any "context" info goes to the parahippocampal cortex. This information goes through the entorhinal cortex where it's taken to the hippocampus.

What part of the brain is believed to spur on sleep spindles?

a. Hippocampus

What is the 2 process model of Sleep Regulation?

dictates ability to fall asleep - Sleep Process S: how much sleep did you get? builds up during day. - Circadian Process Sleep: We have developed rhythm in every component of our biological being.

What is primary insomnia?

difficulty falling asleep after going to bed or after waking up during the night

How does the SCN control cycles of sleep and waking?

efferent axons of SCN that are responsible for organizing sleep/waking cycles terminate in the subparaventricular zone (SPZ). This projects to two brain regions that control wake and sleeping: vlPOA (which is inhibited) and orexinergic neurons (which are excitatory, promoting wakefulness) - activities of these connections varies across day/night cycle

Electro-oculogram (EOG)

electrodes attached around the eyes monitor eye movements

What is lights relation to the circadian rhythm?

exposure to bright lights at the appropriate time eases transition to new circadian patterns

What is process C?

free running circadian rhythm; w/o time cues, body will reset sleep schedule everyday - humans have a 24-25 hour circadian rhythm

What are homeostatic and allostatic factors for sleeping/waking?

homeostatic follows principles that regulate eating and drinking and is control through the presence or absence of adenosine allostatic refers to reaction to stressful (danger, lack of water) situations that override homeostatic control. Mediated by hormonal/neural responses and by neuropeptides (orexin) that are involved in hunger and thirst

which type of memory does the mirror-drawing test evaluate?

implicit procedural

beta activity

irregular, mostly low amplitude waves of 13-30 Hz; desynchrony; reflects the fact that many different neural circuits in the brain are actively processing information. Desynchronized activity occurs when a person is alert and attentive to events in the environment or thinking actively

How does muscle atonia in REM start?

reticular formation inhibition of motor neurons in spinal cord

What is rebound insomnia?

return or increase in insomnia following end of sleep-promoting drugs

parasomnias

sleep walking, talking

stage 1

theta activity; indicates that the firing of neurons in neocortex is synchronized; stage is transition between sleep and wakefulness - during waking period of N1, you see alpha waves. These alpha waves are replaced by theta waves in N1 when you fall asleep.